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Patented Aug. 22, 1916.

Q My ran snares earner FF1E THOMAS J'. GRIFFIN, 013, LOS ANGELES, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGN- MEN TS, T SHARP-HUGHES TOOL COMPANY, OF HOUSTON, TEXAS, A GORPORATIQN OF TEXAS.

- ROTARY DRILL.

Specification of Letters Patent.

Original application filed June 11, 1913, Serial No. 773,031.

Patented Aug. 22, rain. Divided and this application filed February 25,

1915. Serial No. 10,488.

To all whom it may concern:

Be it known that I, THOMAS J. GRIFFIN, a citizen of the United States, residing at Los Angeles, California, have invented a certain new and useful Improvement in Rotary Drills, of which the following is a and exact description, such as full, clear, will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to rotary drills, and particularly to drills of the type in which the cutting means consists of rotatable cutters that scrape off the material from the side wall of the hole when the drill is in operation, this present applicationbeing a division of my application for patent for improvements in rotary drills, filed June 11, 1913, Serial #773,031.

One object of my present invention is to provide a drill of the general type mentioned that comprises a head and a pair of substantially verticallydisposed toothed cutters arranged at the lower end of the head in approximately parallel relation to each other, with their axes disposed at approximately right angles to the axis of rotation of the drill.

Another object is to provide a drill in which the rotatable cutters are housed in the head and are offset slightly with relation to each other or arranged with their axes staggered slightly in a horizontal plane so that the rear edges of the cutters will not drag against the side wall of the hole when the drill is inoperation.

Another object is to provide a drill of the general class mentioned, in which the cutters are housed in the head, the head being preferably provided with two side portions that lie outside of or beyond the cutters, and also having a central or intermediate portion that is arranged between the cutters. And still another object is to provide a rotary-drill of the type mentioned, in which the head is provided with a water course or passage-way or a' plurality of passage-ways which are so disposed that jets of flushing water will be discharged downwardly between the cutters. so as to prevent the disintegrated material from becoming packed in the space between the cutters Figure 1 ofthe drawings is a side eleva tional view of a drill constructed in accordnects the head to the The cutters A of the drill herein ance with my invention, the sleeve that condrill stem being shown in section. Fig. 2 is a vertical sectional view taken on the line 2'-2 of Fig. l; and Fig. 3 1s a horizontal sectional view taken on the line 3-3 of Fig. 1.

Referring to Figs. 1 to 3 of the drawings, which illustrate one form of my invention, 1 designates the head of the drill which is provided at its lower end with two transversely-disposed slots or pockets that are preferably arranged parallel to each other, thus forming two side vbearings 2 and a center bearing 3 at the lower end of the head. The drill is provided with two substantially disk-shaped cutters A that .are arranged in a vertical position and in parallel relation to each other in said .slots or pockets, the center bearing on the head lying between the two cutters A and the side bearings on the head lying beyond or outside of said cutters. The cutters A are provided on their edge portions with cuttlng teeth 4 that extend transversely across the edges of same, and each of said cutters is rotatably mounted on a shaft br pin 5 whose inner end is. supported by the center bearing 3 on the head and whose outer end is supported by one of said side bearings 2. In the preferred form of my invention, as herein shown, the cutters A are offset slightly with relation to each other or arranged in such rotation are staggered slightly in a hori: zontal plane, as shown in Fig. 3, the purpose of arranging the cutters in this manner being to prevent the rear edge portions of the cutters from dragging against the side wall of the hole when the advancing edges or front portions of the cutters are scraping off the material at the side wall ofthe hole. shown have amanner that their axes of their edge portions beveled inwardly toward the vertical axis of the drill head so as to form a cutting edge 6 on the outer edge of each cutter that will shear ofi the material from the side wall of the hole when the head of the drill is rotated in the direction indicated by the arrow in Fig. 3. I wish it to be understood, however, that my invention is not limited to a drill in which the cutters are arranged parallel to each other and provided with beveled edges, arrangement of the cutters and the shape of for the particular on the cutters givin the cutting or crushingportions of the cutters could be changed 1n various ways without departing from the spirit of my invention.

When the drill is in operation the cutters A scrape Off the material from the side wall of the hole and also disintegrate the. material at the bottom of the hole, the teeth 4 the cutters sufiicient traction to insure t eir turning on their axes, and thus continually bringing different portions of the cutters into operative position to act on the side wall of the hole.

The pins or shafts 5 on which the disks or cutters A are rotatably mounted can be se-- cured to the head in any suitable manner, as, for example, by means of pins 7 in the side bearings 2 of the head that pass transversely through the outer portions of the shafts 5.

As shown in Fig. 2, the head 1 is provided with water courses or passage-ways 8, which are preferably arranged at an angle to the vertlcal axis of the head adjacent the lower end of the head in such a manner that jets of water will be discharged'downwardly between the cutters and laterally toward the side wall of the hole, so as to prevent the disintegrated material from becoming packed between the cutters or from becoming clogged between the lower end of the head of the drill and the bottom of the hole.

In view of the fact that the disks or cut ters A are housed in the head of the drill, there is very little liability of the disintegrated material or cuttings becoming packed around the cutters in such a manner that the cutters will not rotate on their axes; and another advantage of a drill of this construction is that substantial bearings on the heads are provided for both ends of the shafts 5 on which the cutters A are rotatably mounted. 7

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is:

1. A drill composed of a head and two vertically-disposed cutters arranged on said head in approximately parallel relation to each other and spaced apart, the axis of one of said cutters being offset or stag ered slightly with relation to the axis 0 the other cutter so that the rear edges of the cutters will not drag against the side wall of the hole and each cutter being arranged substantially midway the center axis of the head and the outside of the head.

2. A drill composed of a head and two substantially disk-shaped cutters housed in the head and arranged in an upright position and offset with relation to each other at points approximately midway the vertical axis and the outside of the head ortions of each cutter projecting laterally f f'om the head so as to remove the material from the side wall of the hole.

3. A drill composed of a head provided with a single center bearing and two side bearings, and two substantially verticallydisposed cutters housed in said head and rotatably mounted on shafts whose inner and outer portions are supported by said center and side bearings, said cutters having portions that project laterally from the head and remove the material from theside wall of the hole.

4. A drill composed of a head, and two rotatable cutters on said head whose axes of rotation are disposed at right angles to the axis of rotation of the drill head, said cutters being arranged in parallel relation to each other, with the axis of one cutter olfset or staggered slightly with relation to the axis of the other cutter and each cutter being located substantially midway the vertical axis of the head and the outside of the head.

5. A rotary boring drill composed of a head provided at its lower end with two parallel pockets that extend transversely through the head at points substantially midway the vertical axis and the outside face of the head, and two vertically-disposed, toothed cutters arranged in said pockets in parallel relation to each other and in such a manner that they scrape off the material at the side wall of the hole.

In testimony whereof I hereunto aflix my signature in the presence of two witnesses, this seventeenth day of February, 1915.

THOMAS J. GRIFFIN.

Witnesses:

D. R. BEATTY, BERTHA FREITAG.

Correction in It is hereby certified that in Letters Patent No. 1,195,209, granted August 22, 1916, upon the application of Thomas J Griffin, of Los Angeles, California, for an improvement in Rotary Drills, an error appears in the printed specification requiring correction as follows: Page 2, line 63 claim 2, after the word head insert acomma; and that the said Letters Patent should be read with this correction therein that the same mayvconform to the record of the case in the Patent Office.

Signed and sealed this 26th day of September, A; D., 1916.

' F. W. H. CLAY,

Acting Commissioner of Patents.

' [SEAL] 

